In recent years, a charged particle beam device such as a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) may include a spherical aberration correction device (hereinafter, also referred to as an “aberration corrector”). The aberration corrector is used to correct a spherical aberration (Cs) of an objective lens, which is a main factor that limits the resolving power of a TEM or a STEM. An aberration corrector is known which includes two multipole lenses generating hexapole fields, and two rotationally symmetric lenses (transmitting lenses) that are disposed therebetween (for example, refer to PTL 1).
The aberration corrector corrects a positive Cs of an objective lens by generating a negative Cs. However, an extra aberration, which is called a parasitic aberration, occurs due to imperfectness of the aberration corrector, that is, the positional offset of an individual pole of a multipole lens, a variation in magnetic characteristics of a pole material, or the like. Third-order or lower occurring parasitic aberrations are a two-fold symmetry first-order astigmatism (A1), a one-fold symmetry second-order coma aberration (B2), a three-fold symmetry second-order astigmatism (A2), a two-fold symmetry third-order star aberration (S3), and a four-fold symmetry third-order astigmatism (A3). In addition to the correction of the spherical aberration Cs, the correction of these parasitic aberrations is essential for adjusting the aberration corrector.